A terrain tree that was made from a low poly model would not rotate when spawned.

Gaia randomly rotates terrain trees when spawning them as this creates a more natural feel to the environment, however it did not seem to be working, and on further testing the behaviour was replicated directly with the unity terrain tree tool on the terrain itself, and is not related to Gaia, but to a quirk of unity terrain.

To resolve:

  1. Create empty game object
  2. Add LOD group
  3. Add mesh to LOD group
  4. Repeat for next LOD
  5. Save as Prefab

They can now be treated like any other terrain tree in Unity and will now rotate correctly when spawned. 

Solution courtesy of Kael!